In recent years, research and development of organic light emitting elements have been progressing. An organic light emitting element is a light emitting element utilizing an electroluminescence phenomenon of an organic material, and has a pair of electrodes consisting of an anode and a cathode, and a light emitting layer sandwiched between the electrodes. In addition, for example, a hole injection layer and a hole transport layer or a combined hole injection and transport layer are interposed, as required, between the anode and the light emitting layer, whereas an electron injection layer and an electron transport layer or a combined electron injection and transport layer are interposed, as required, between the cathode and the light emitting layer. Since the light emitting layer, the hole injection layer, the hole transport layer, the combined hole injection and transport layer, the electron injection layer, the electron transport layer, and the combined electron injection and transport layer each fulfill an intrinsic function such as light emission, electric charge injection or transport, these layers are generically referred to as “function layer.”
In an organic display of a full-color display type, such organic light emitting elements correspond to sub-pixels for each of RGB (Red-Green-Blue) colors, wherein adjacent RGB sub-pixels together form a single pixel, and the pixels are arranged in a matrix form to form an image display region.
In such an organic display, in order to obtain high-definition images, it is demanded that the pixels be formed with one side of each pixel being in a minute size of not more than approximately 500 μm. In a system where the pixel size is thus minute, the film thickness of the function layer in each element should be set as small as several tens to several hundreds of nanometers.
In manufacturing an organic display, there is a step of forming a function layer over an electrode. In this step, there has been proposed a wet system in which a solution containing a functional material and a solvent is applied to an upper side of the electrode, and the applied solution is dried to form the function layer.